Fire tower



1961 N. M. NEHRBASS 3,013,640

FIRE TOWER Filed Aug. 20. 1959 l INVENTOR 25 70-4 26. 2M 7% %Mn% ATTORNEY United States Patent 3,013,640 FIRE TOWER Neil M. Nehrhass, Cameron House, Lafayette, La. Filed Aug. 20, 1959, Ser. No. 835,998 3 Claims. (Cl. 189-12) This invention relates to a sectional observation tower or the like such as may be employed as a fire watch tower.

It is an important object of the invention to provide such a tower which may be readily erected from prefabricated sections joined together to form an extremely rigid and yet light weight structure. By virtue of its fabricated construction and its extremely simplified mode of assembly, the tower is especially adapted for erection in rugged terrain and at poorly accessible locations such as may be encountered in the national and state forests, Etc.

In order to achieve the foregoing objects, the invention employs a plurality of main tower sections of identical construction which may be capped by a modified section having an enclosed observation platform thereon, together with novel coupling units all of similar standardized construction, each adapted to be interposed between and to interconnect the adjoining ends of adjacent main sections to form a structure of rigid construction throughout. a

Moreover, there is included in each coupling unit or section a plurality of connection elements or attachments disposed substantially at the horizontal plane of juncture between adjoining sections whereby guys or stays may extend from each of these levels to suitable anchorage points at or near the ground level to better maintain the vertical alignment of the respective sections and the vertical position of the tower as a whole.

In particular, the invention contemplates the formation from prefabricated sections or units of a tower which may be of varying heights depending on the number of sections employed but which, in any event, may be provided with a continuous spiral stairway from bottom to top. The invention contemplates providing a spiral series of such steps in each main section, together with one or more steps constituting part of each coupling unit, the several main sections and their coupling unit being so arranged that the steps form a continuous spiral to the top of the tower.

A tower structure incorporating the foregoing features of the invention, as well as other incidental features and advantages, is illustrated in the accompanying drawings, in which:

FIG. 1 represents a front-elevation of a tower structure in accordance with the invention;

FIG. 2 is an enlarged fragmentary sectional view taken on the line 22 of FIG. 3; and

FIG. 3 is an enlarged section on the line 3-3 of FIG. 2.

Referring now in detail to the accompanying drawings, as shown in FIG. 1, the tower in its entirety is formed of any suitable number of verticallysuperposed main tower sections designated A, B and C, of identical construction which may be capped by a somewhat modified top section designated D in its entirety defining a preferably enclosed observation platform E.

The exact structural details of the enclosed platform B may be varied to suit different uses or functions to be served by the tower, and is not of the essence of the invention.

It will be seen that the several main sections A to D, inclusive, of the tower are rigidly interconnected by coupling units, each designated F in its entirety.

-Each of the main units A, B and C, as above mentioned, is of similar construction to the others and each comprises a rigid vertical supporting standard dis- 'ice posed at the center thereof, same, if desired, being of tubular construction and of relatively large diameter. Supported from this standard 10 are a plurality of horizontal steps 12 which radiate in spiral formation from the standard and are suitably fixed to the standard as by welding, clamping, or the like, at their radially inner ends.

Preferably the radially outer ends of the respective steps of each section are interconnected and secured against relative rotary displacement by a spiral peripheral band 14 shown generally in FIG, 1. Disposed circumferentially around the outer periphery of the spiral defined by the steps is a plurality of rigid vertical braces 16 which are uniformly circumferentially spaced in the respective sections, there being four such braces to each section in the preferred embodiment and these being angularly or circumferentially spaced at intervals of though this particular arrangement and disposition is by no means essential.

The respective braces 16 of each section will preferably be rigidly secured as by welding, bolting, or the like, to the ends of the steps and/or the spiral band 14 of each section to form therewith a unitary structure.

The coupling sections or units F which interconnect the ends of relatively adjoining main sections are each of identical structure, each comprising a rigid annulus 18 of an internal diameter to surround the vertical braces 16 at the adjoining ends of a pair of main sections. The annulus 18 is thus disposed in a horizontal plane and has a series of vertical coupling sleeves 21) secured thereto around its inner periphery at uniformly angularly spaced positions (in the present instance 90 apart) for reception of the upper and lower ends of the braces 16 of two sections of an adjoining superposed pair. It will be seen that the ends of the braces of the respective sections are received in opposite ends of the coupling sleeves 2t and are brought together in endwise abutting relationship in true vertical alignment. For securing'the braces 16 within the coupling sleeves 20 there may be provided usual pins or bolts 22 adapted for insertion through registering openings in the coupling sleeves and braces respectively in usual manner.

At the center of each coupling unit is concentrically disposed at central vertical sleeve 24. This sleeve 24 is open at both ends and has an internal diameter proportioned to snugly receive the adjoining ends of thecentral standards 10 of two interconnected main sections, these ends being normally brought into abutting relation in a common plane with the ends of braces 16 and secured in fixed position against relative vertical displacement by means of diametrically disposed pins or bolts 26.

Preferably each such central sleeve 24 is provided with a short series of spirally arranged steps designated 12a, 12b and 120, respectively, in the drawings, thesebeing suitably connected to the annulus 18 to therewith form a rigid unit. To this end it will be seen that the steps 12a, 12b, and 12c in the present embodiment jointly occupy an arc or angle equal to the angular. distance between adjoining coupling sleeves 2 0 and .as shown in FIG. 3 the radially outer ends of the steps 12a and 12c at their relatively opposed circumferential edges are rigidly connected to the annulus 18, preferably through two relatively adjoining sleeves 20 thereof, the steps being welded or otherwise suitably secured to these sleeves. The middle step 12b, which will be at the level of the annulus 18, may be rigidly connected thereto at its outer end in any suitable manner.

In assembling the several sections to form a complete tower, the lowermost section A will first be erected preferably on a suitable supporting base or foundation generally designed 28, whereupon a coupling unit F is secured fixedly at the upper end of the erected unit A with the central standard 10 and the several braces 12 received in its respective sleeves 24 and 2G and secured thereinby means of the bolts 26 and 22, respectively. Subsequently, the second main section B is elevated and p'aced in position with the lower ends of its braces 16 and central standard 18' received in the upper ends of the respective sleeves 20 and 24 and then secured in place by the bolts or pins 22 and 26.

Additional sections, including the top section D with its observation platform E, are subsequently erected in similar manner.

During the process of erection, the coupling sections P will be oriented or rotatably disposed in such a manner that their respective steps 12a, 12b and 126 will in each case form with the adjoining main sections a continuous spiral stairway to the top of the tower. It will be seen that in the present instance the spiral stairway within the main sections A, B and C will connect with a stairway 30 leading outside of the confines of the braces 16 and to a port or opening (not shown) in the floor 32 of the enclosed platform.

In order that the completed tower may be accurately maintained in vertical position and reinforced against high winds or other forces tending to deflect it from the vertical position, the respective coupling units 18 are formed with eyelets 34 or other suitable attaching means for stays or guys 36 which are suitably anchored at points 38 adjacent or at the ground level as indicated by the line G. Preferab'y the said eyelets or attachments 34 of the respective coupling units 18 are similarly angularly disposed so that they will extend in several vertically aligned series, the guys 36 of each such series thus extending to a common anchorage point 38 to thus facilitate not only the assembling of the tower but the adjustment of the tension of the guy wires for the purpose of maintaining the vertical alignment of the respective sections A to D, inclusive.

In this app ication I have shown and described only the preferred embodiment of the invention simply by illustrating the preferred mode of practicing the invention. However, I recognize that the invention may be modified in various ways and that its individual details are capable of alteration, all without departing from my invention. Accordingly, the drawings and description herein are merely illustrative in nature rather than restrictive.

Having thus described the invention, I claim:

1. A sectional fire tower comprising a plurality of vertical'y superposed main sections, each said section comprising a rigid central vertical supporting standard, a plurality of horizontal steps radiating in spiral formation from said standard and fixed thereto at their inner ends, a spiral band extending around and interconnecting the outer peripheral edges of the said steps to secure said steps against relative rotary displacement, a plurality of rigid vertical braces spaced circumferentially of the steps at regular angular intervals around the periphery of said steps and said spiral band and uniformly radially spaced from said central standard, in combination with a coupling unit interposed between and interconnecting each relatively adjoining pair of said relatively superposed main sections, said coupling unit comprising a rigid annulus of an internal diameter to surround said vertical braces at the interconnected ends of said main sections, vertical coupling sleeves rigidly carried by said annulus, said sleeves being relatively circumferentially spaced at the same angular intervals as said braces and receiving the adjoining interconnected ends of the said vertical braces, means securing said braces within said sleeves, a central sleeve disposed concentrically within said annulus and receiving the relatively adjoining ends of the supporting central standards of said pair of sections, and a plurality of steps extending radially between and rigidly interconnecting said central sleeve and said annulus, said steps fully occupying but being confined within one of said angular intervals.

2. A sectional fire tower comprising a plurality of vertically superposed main sections, each said section comprising a rigid central vertical supporting standard, a plurality of horizontal steps radiating in spiral formation from said standard and fixed thereto at their inner ends, a plu rality of rigid vertical braces spaced at regular intervals around the periphery of the spiral defined by the outer periphery edges of said steps, in combination with a coupling unit interposed between and interconnecting each relatively adjoining pair of said relatively superposed main sections, said couping unit comprising a rigid annulus of an internal diameter to surround said vertical braces, vertical coupling sleeves rigidly carried by said annulus, said sleeves receiving the upper and lower ends respectively of the vertical braces of said interconnected sections, means securing said braces within said sleeves, a central vertical sleeve disposed concentrically Within said annulus and receiving the reatively adjoining upper and lower ends of the supporting standards of said pair of sections and a horizontal step extending radially between and rigidly interconnecting said central sleeve and said annulus.

3. A sectional fire tower comprising a plurality of vertically superposed main sections, each said section comprising a rigid vertical and centrally disposed supporting standard, a plurality of horizontal steps radiating in spiral formation from said standard and fixed thereto at their inner ends, and a plurality of rigid vertical braces spaced at regular intervals around the outer periphery of the spiral defined by said steps, in combination with a coupling unit interposed between and interconnecting each adjoining pair of said main sections, said coupling unit comprising a rigid annulus surrounding said spiral steps at the level of the interconnected ends of said main sections, vertical coupling sleeves rigid'y carried by said frame and receiving and secured to the interconnected ends of the said respective vertical braces, a central vertical sleeve and means securing same concentrically within said annulus for receiving and interconnecting the relatively adjoining ends of the supporting standards of said sections.

References Cited in the file of this patent UNITED STATES PATENTS 348,908 Horrocks Sept. 7, 1886 740,917 Prouty Oct. 6, 1903 1,521,422 Boyd Dec. 30, 1924 2,387,120 Cohen Oct. 16, 1945 2,431,610 Cohen Nov. 25, 1947 FOREIGN PATENTS 2,940 Great Britain July 18, 1879 323,538 Italy Dec. 27, 1934 

